argumentAxis

For charting, the polar coordinate system is used to determine each point uniquely on a plane through two numbers, the argument and the value of the point. A circular and straight lines (the axis of arguments and the axis of values) are specified to define the coordinates. To define the argument axis, use the argumentAxis configuration object. To define the value axis, use the valueAxis configuration object. To set the properties of all axes to a common value, use the commonAxisSettings configuration object. This object exposes the properties that can be specified for all axes simultaneously. Note that the value specified for an axis individually (in the argumentAxis or valueAxis object) overrides the value specified in the commonAxisSettings object.

This example shows the argument axis of a continuous type. Here, the axis' start angle is 90 degrees and labels are customized to indicate degrees as the unit of the axis' values. In addition, the minor grid lines of the axis are made invisible and major grid lines are drawn with an interval equal to 10.

argumentType

The type of the axis values is determined based on the type of the values specified in the corresponding data source field of the chart's series. If arguments are specified as numeric values in a series data source, the argument axis values will also be of the numeric type. The same logic is used when string or date-time arguments are specified in the data source.

In some scenarios, you may need the type of the arguments that are specified in the data source to be converted to another type. In this instance, specify the desired type for the axis values using the argumentType property.

axisDivisionFactor

The argument axis is divided by default so that the labels corresponding to the ticks/grid lines do not overlap each other. If you need to make the axis tick interval larger or smaller, use the axisDivisionFactor property. This property value is a coefficient used internally to calculate the distance between axis labels. This allows you to set an axis division without knowledge of the actual axis values.

NOTE

This option is used for continuous and logarithmic argument axes only.

categories

If you specify the chart's data using a common array of objects, these objects may be displayed in a random order. If you set the chart's data for each series individually, the order in which the series are positioned in the series array can also be random. In these instances, the resulting argument order on the discrete argument axis may not be appropriate. To specify the order of categories (arguments on a discrete argument axis), assign an array of category names to the categories property.

Here, years in the chart's data source are represented as strings. By default, they will be displayed on the argument axis in the same order as they are listed in the data source. To display them in another order, the categories option is used.

A constant line is a straight line that can be used to display, for example, an asymptote of a graph. To display constant lines on a chart, assign an array of objects specifying the options of each constant line to the constantLines field. It is necessary to set the value option within these objects. The other options can be set if required.

You can customize the appearance of all the argument axis constant lines at once. For this purpose, use the argumentAxis | constantLineStyle configuration object. Note that the options that are set within the argumentAxis | constantLine object override the corresponding options that are set within the argumentAxis | constantLineStyle object.

Use this object to set the appearance options for the constant lines of both the argument and value axes. For example, you can change the color, dash style and width of the line using corresponding options or define the look of the labels using the label object.

To specify styles for the constant lines of the argument and value axis separately, use the constantLineStyle object within the argumentAxis or valueAxis configuration object correspondingly. Note that the options that are set within these objects override the corresponding options that are set within the commonAxisSettings | constantLineStyle object.

In addition, you can define the appearance of each constant line individually. For more information, refer to the argumentAxis | constantLines or valueAxis | constantLines object description.

In the following example, several appearance options of the argument axis constant lines are changed. These lines are drawn in the yellowgreen color with a 2-pixel width. The dash style of the lines is changed to longDash. In addition, the constant line labels are colored in lightskyblue.

discreteAxisDivisionMode

Specifies whether ticks/grid lines of a discrete axis are located between labels or cross the labels.

When a discrete axis is divided, its ticks/grid lines are located between labels by default. If this is not appropriate, use the discreteAxisDivisionMode property to set the required mode for positioning ticks and grid lines on a discrete axis.

In the following example, you can note the difference between two modes of positioning ticks and grid lines on discrete axes. Use the drop-down list in the bottom to change the value of the discreteAxisDivisionMode option.

firstPointOnStartAngle

Specifies whether or not to display the first point at the angle specified by the startAngle option.

In the example below, the fist category, "N" (north), is displayed directly to the north of the chart, because the "firstPointOnStartAngle" option is set to true and the start angle coincides with the north direction.

Grid lines are the reference lines used to improve the readability of a chart's visual data. The grid object exposes the properties that allow you to specify visibility and appearance settings for axis grid lines. To learn more about axis grid lines and their options, refer to the Grid topic.

hoverMode

Specifies the elements that will be highlighted when the argument axis is hovered over.

allArgumentPoints
The points that correspond to the argument that is currently hovered over are highlighted. To change the way the points are highlighted, set the options within the series | point | hoverStyle object.

inverted

When an axis is inverted, the maximum and minimum values are reversed. As a result, the axis values increase in a direction that is opposite to the initial direction. The chart series are also inverted.

Axis labels represent textual values for axis ticks, which are not visible by default. To specify custom settings for the argument axis labels, use the label configuration object. To set a common value for labels on all axes, use the commonAxisSettings | label configuration object. This object exposes the properties that can be specified for labels on all axes at once. Note that values specified for the argument axis individually (in the argumentAxis | label object) override values that are specified for all axes (in the commonAxisSettings | label object).

logarithmBase

By default, ticks on a logarithmic axis are generated on a base of 10, i.e., 0.1, 1, 10, 100, 1000 etc. But you can specify a base you require using the logarithmBase option. For example, if you set this option to 5, the following ticks will be generated: 0.5, 5, 25, 125, 625, etc.

NOTE

The value assigned to the logarithmBase option should be greater than 1.

In addition to the major grid built on major ticks, the dxPolarChart widget provides the minor grid that is built on minor ticks. The lines of the minor grid extend from the minor ticks throughout the entire chart's plot.

NOTE

Neither minor ticks, nor the minor grid can be used if the axis is discrete.

To specify the appearance of grid lines, use the options of the minorGrid object. Declared within the commonAxisSettings object, the minorGrid object changes the appearance of value and argument axes simultaneously. To change the appearance of the value or argument axis individually, declare the minorGrid object in the argumentAxis or valueAxis object respectively. Settings specified individually override those that are set in the commonAxisSettings object.

To make the minor grid visible, set the visible option of the minorGrid object to true. Additionally, you can change the color, opacity and width of the grid lines using the corresponding options.

NOTE

We recommend you use the minor grid only in conjunction with the major grid.

In addition to major ticks, the dxPolarChart widget provides the capability to draw minor ticks. Minor ticks divide an axis segment that lies between two neighboring major ticks. To specify how to generate minor ticks, use the minorTickInterval or minorTickCount options.

To configure the appearance of minor ticks, use the options of the minorTick object. Declared within the commonAxisSettings object, the minorTick object sets options for all minor ticks. To change the appearance of the minor ticks that belong to the argument or value axis individually, declare the minorTick object in the argumentAxis or valueAxis object respectively. Settings specified individually override those that are set in the commonAxisSettings object.

By default, minor ticks are hidden. To make them visible, assign true to the visible option of the minorTick object. Additionally, you can change the color, opacity and width of the minor ticks using the corresponding options.

To divide a lengthy chart axis into shorter segments, major and minor ticks are used. Major ticks are accompanied with axis labels. Between each pair of neighboring major ticks, several minor ticks reside. Minor ticks are required when major ticks are far from each other. To set a custom minor tick interval, use the minorTickInterval option. If this option is not set, minor ticks are arranged automatically.

In case your axis displays numbers, assign a numeric value to this option. If the axis displays dates, assign one of the predefined string values. To set the interval to several days, hours, etc., assign an object with the corresponding field specified (days, hours or another field). Note that this object must contain only one of the fields described in this section.

NOTE

The minorTickInterval option can be applied to a continuous axis only. For logarithmic axes, use the minorTickCount option.

originValue

Normally, dxPolarChart calculates the origin value of the argument axis automatically depending on the smallest argument of series points. In case you need to specify it explicitly, use the argumentAxis | originValue option.

NOTE

If the series contains points whose argument is less than the specified origin value, these points will reside to the left from the argument axis' origin. This may lead the start and end of the resulting diagram to overlap.

period

This option makes sense when you have a continuous argument axis. By default, all the argument values in the data source fit one circle of the argument axis. You can use the period option to set the interval of argument values that fits one circle of the argument axis. For instance, the argument values from 5 to 10 can be displayed with a period set to 5 in two argument axis circles: from 0 to 5 and from 6 to 10.

setTicksAtUnitBeginning

This property is used when a continuous axis of the 'date-time' value type is divided. If this property is set to true, axis ticks/grid lines are set at the beginning of date-time units (months, days, years, etc.). The following examples will help you understand the logic.

Strips are the highlighted areas in a chart within the defined range of values (minimum and maximum) for an axis to which they belong. In general, strips are used to visually represent a range of values behind a series to trace whether the series points' values fall in or out of that range. For more details on strips, refer to the Strips topic.

To define strips for the argument axis, use the strips array. Each object in this array should contain the startValue, endValue and color fields specified. Note that specifying all these fields is necessary for a strip to be displayed.

In addition, you can show a label with descriptive information on a strip. To set the text for a label, use the strip's label object.

If you need to set similar values for all strips of all axes, use the commonAxisSettings | stripStyle configuration object. It exposes the properties that can be specified for strips of all axes at once. Note that the values specified for the argument axis individually (in the argumentAxis | strips object) override the values that are specified for all axes (in the commonAxisSettings | stripStyle object).

Strips are the highlighted areas of a chart within a defined range of values (maximum and minimum) for an axis to which they belong. In general, strips are used to visually represent a range of values behind a series, to trace whether the series point values fall in or out of that range. For more details on strips, refer to the Strips topic.

To set options for configuring strip style, define the stripStyle object within the argumentAxis or valueAxis configuration object. To set common options for all strips in a chart, define the stripStyle object within the commonAxisSettings configuration object. Note that the values that are set for an individual axis override the corresponding common values.

Ticks divide an axis into equal sections by a step whose value is determined automatically, or by the tickInterval and axisDivisionFactor options of an axis. Ticks improve the readability of charts, but are not visible in the dxPolarChart widget by default. To set up tick configuration options, define the tick object within the argumentAxis or valueAxis configuration object. To set common options for all ticks in a chart, define the tick object within the commonAxisSettings configuration object. Note that the values that are set for an individual axis override the corresponding common values.

Use this option to divide the scale by ticks in a specified interval one from another. If this option is not set, ticks are automatically arranged so that their labels do not overlap each other.

In case of a numeric axis, assign a numeric value to this option.

If the axis is of the date-time type, assign one of the predefined string values or an object to this option. The object's fields specify the number of days, hours, etc.

When you use a logarithmic axis, ticks are generated on a base of powers. For example, assume that the logarithm base is 10. Then, if the tick interval is 1, ticks are generated at 0.01, 0.1, 1, 10, 100, 1000, 10000, etc. If the tick interval is 2, ticks are generated at 0.1, 10, 1000, etc.

NOTE

The specified tick interval can be changed internally if its value leads to label overlapping. If you need to prohibit an automatic tick arrangement in this situation, specify the argumentAxis | label | overlappingBehavior option.

To set the tickInterval option for several axes at once, use the commonAxisSettings configuration object. To set this option for an individual axis, use the argumentAxis or valueAxis configuration object.

type

The 'discrete' type is set when string arguments are specified in the data source of the chart's series. The discrete axis is divided by the values (called categories) that are specified as arguments in the data source. The categories order can be specified by the categories property, if the order used in the data source is not appropriate.

The 'continuous' type is set when numeric or date-time arguments are specified in the series data source. The continuous axis is divided automatically.

The 'logarithmic' type can be set when numeric values are specified in the series data source. The logarithmic axis is useful when you visualize a dataset of rapidly-growing values. Each axis tick represents a particular value that is raised to the next power in turn. This particular value is specified by the logarithmBase option. For example, if you set this option to 5, the following ticks will be generated: 50, 51, 52, 53 etc.

On continuous and logarithmic axes, ticks and grid lines are positioned so that their labels do not overlap each other. In addition, you can set a custom tick interval (the tickInterval or axisDivisionFactor options).

NOTE

If you require a discrete axis when numeric or date-time arguments are specified in the data source, set the type option to 'discrete' explicitly.

visible

Indicates whether or not the line that represents an axis in a chart is visible.